In the field of high-speed computers, performance is enhanced through high-density packaging of high-speed electrical devices. Typically, high-speed devices exhibit above-average power consumption characteristics. High power consumption in turn leads to high heat generation. A cooling apparatus must be able to dissipate heat from circuit devices and yet not constrain circuit assemblies.
U.S. Pat. No. 4,628,407 to Aug. et al. and assigned to Cray Research, Inc., the Assignee of the present invention, describes a typical printed circuit board used in a high performance computer. In this system, a printed circuit board stack is disclosed which includes a heat-conducting plate situated therein. The printed circuit boards contain thermally conductive pads from each circuit device through the printed circuit board to locations in contact with the cooling plate. This system provides good heat dissipation properties, but the cooling plate described therein does not adequately coexist with the packaging designs of newly developed printed circuit board stacks.
U.S. Pat. No. 4,514,784 to Williams et al., and assigned to Cray Research, Inc., the assignee of the present invention, describes an interconnected multiple circuit module. Each circuit module comprises a pair of circuit board assemblies disposed on opposite sides of a central cooling plate. Each circuit board is maintained in a predetermined spaced-apart relationship with the cooling plate. An array of pins extend perpendicular through each circuit module. Clearance holes are provided in the cooling plate so that there is no electrical contact between the pins and the cooling plate. This system describes a method for z-axis electrical interconnection of circuit boards, but the cooling plate described therein does not adequately support such electrical interconnection.